I don't know if you are still having noise problems or not, but you may want to consider the following:
Try to run your power leads (12V, ACC, GND) from the opposite side as your speaker leads. If they run parallel to one another, as in your image above, you are prone to line noise. Is it possible to bring in your power leads from the right side of the car, rather than through the center console? That might improve your situation, especially since you have additional items on ACC power (like the charger dock).
You might want to invest in larger wires for your power leads. I don't think you need "0-guage" wire, but bigger wires usually mean more insulation, thus potentially reducing any unwanted noise even further.
I hope those suggestions help, and congratulations on a very nice project!
Thanks for your suggestions Gr8rt3k, I already tried to run power wires far from speaker wires, or with better quality wires but nothing changed. The problem arises from the desk dock, probably because it was not meant to be installed in a car :) For me, the desk dock has components inside that are too close each other and any sort of shielding.
I'll check with the BT audio recevier and trying to bypass this issue :)
I have the same dock as you and have the same bad noise problems. I know it isn't my audio setup because it worked fine when I had the carputer setup, and also worked fine when I had my iPhone setup (temp system while I was building the tablet version). as soon as I plug the charger cable and the audio out cable into the dock I get bad static noise. I had to turn the gain down on all channels of my amp down to 45%. It works for now (too low to here the hissing and popping) but I have to turn up the volume of the tablet almost to 100% to get the good sound/bass I had with the carputer. My amp is an Alpine PDX-5.
I have received the cheap BT audio receiver, here are some pics
so i disconnected the audio jack from the dock (the one that goes to the amplifier) and connect it to the receiver
but.. more noises than ever!!
Yes, it is definitely cheap hardware ($8) so I bought on ebay a Belkin Bluetooth Music Receiver (about 26 eur)
I made some home test and it seems ok, but to try it in car I need to modify the power cable to gather power from a 12v -> USB adapter
An issue I have found is that tablet won't reconnect automatically to the bt audio receiver. The Belkin is in the paired devices list, but I need to tap on it to have connection. Is there any app that can do an auto connection to a preferred bt device?
I saw the TuneLink BT receiver and its correspondant app that has this feature.. but it costs about $ 100 so if I could do without it it would be better :)
tunelink is $77 shipped on amazon, might be cheaper on ebay.
If I do decide to get a BT receiver, it will HAVE to auto connect. I'm trying to make this as easy as possibly, as in turn the key, and go.
i use A2DPconnect and it works well for me. i also integrates with tasker which is even better automation-wise.
@daclothe: I cant'f find anything similar in the Play Store.. is this http://code.google.com/p/a2dp-connect/ that you are referring?
How do you set tasker to automatically connect? Did you let it check at regular basis if the desired a2dp device in in range?
That's the one...you could set it to check in intervals (every 15 minutes) or just have it connect when the tablet receives power. Seems to work pretty well.
You could also try Llama. Its easier to use than Tasker IMO.
Sent from my Galaxy Nexus using Tapatalk 2
Thanks for the tip.
I am not yet sure how I want to set up the power source: at the moment the tab is connected to switched +12v, so it is powered when car is running, and uses its battery when car is off. In this case it's ok to let the tab check and connect a2dp device when engine starts.
But I'm evaluating the possibility to hardwire the tab to permanent +12v so it could be up and running all the time, letting me do remote control even when car is off, at parking etc. For this to work, I have to 'detect' the car state to connect a2dp device and start/stop music. My idea was "when the tab finds Belkin BT device - or when that device asks to connect - the car is ON so: connect BT device (a2dp and obd2), start music, airplane mode off etc"
I understand that standard a2dp devices did not connect itself to the tab - except the TuneLink? Perhaps I should try to let tasker check every 5 seconds if a2dp device is found, and if yes.. start the "car on" task.